1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * PC Watchdog Driver
   4 * by Ken Hollis (khollis@bitgate.com)
   5 *
   6 * Permission granted from Simon Machell (smachell@berkprod.com)
   7 * Written for the Linux Kernel, and GPLed by Ken Hollis
   8 *
   9 * 960107	Added request_region routines, modulized the whole thing.
  10 * 960108	Fixed end-of-file pointer (Thanks to Dan Hollis), added
  11 *		WD_TIMEOUT define.
  12 * 960216	Added eof marker on the file, and changed verbose messages.
  13 * 960716	Made functional and cosmetic changes to the source for
  14 *		inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  15 * 960717	Removed read/seek routines, replaced with ioctl.  Also, added
  16 *		check_region command due to Alan's suggestion.
  17 * 960821	Made changes to compile in newer 2.0.x kernels.  Added
  18 *		"cold reboot sense" entry.
  19 * 960825	Made a few changes to code, deleted some defines and made
  20 *		typedefs to replace them.  Made heartbeat reset only available
  21 *		via ioctl, and removed the write routine.
  22 * 960828	Added new items for PC Watchdog Rev.C card.
  23 * 960829	Changed around all of the IOCTLs, added new features,
  24 *		added watchdog disable/re-enable routines.  Added firmware
  25 *		version reporting.  Added read routine for temperature.
  26 *		Removed some extra defines, added an autodetect Revision
  27 *		routine.
  28 * 961006	Revised some documentation, fixed some cosmetic bugs.  Made
  29 *		drivers to panic the system if it's overheating at bootup.
  30 * 961118	Changed some verbiage on some of the output, tidied up
  31 *		code bits, and added compatibility to 2.1.x.
  32 * 970912	Enabled board on open and disable on close.
  33 * 971107	Took account of recent VFS changes (broke read).
  34 * 971210	Disable board on initialisation in case board already ticking.
  35 * 971222	Changed open/close for temperature handling
  36 *		Michael Meskes <meskes@debian.org>.
  37 * 980112	Used minor numbers from include/linux/miscdevice.h
  38 * 990403	Clear reset status after reading control status register in
  39 *		pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  40 * 990605	Made changes to code to support Firmware 1.22a, added
  41 *		fairly useless proc entry.
  42 * 990610	removed said useless proc code for the merge <alan>
  43 * 000403	Removed last traces of proc code. <davej>
  44 * 011214	Added nowayout module option to override
  45 *		CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  46 *		Added timeout module option to override default
  47 */
  48
  49/*
  50 *	A bells and whistles driver is available from http://www.pcwd.de/
  51 *	More info available at http://www.berkprod.com/ or
  52 *	http://www.pcwatchdog.com/
  53 */
  54
  55#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  56
  57#include <linux/module.h>	/* For module specific items */
  58#include <linux/moduleparam.h>	/* For new moduleparam's */
  59#include <linux/types.h>	/* For standard types (like size_t) */
  60#include <linux/errno.h>	/* For the -ENODEV/... values */
  61#include <linux/kernel.h>	/* For printk/panic/... */
  62#include <linux/delay.h>	/* For mdelay function */
  63#include <linux/timer.h>	/* For timer related operations */
  64#include <linux/jiffies.h>	/* For jiffies stuff */
  65#include <linux/miscdevice.h>	/* For struct miscdevice */
  66#include <linux/watchdog.h>	/* For the watchdog specific items */
  67#include <linux/reboot.h>	/* For kernel_power_off() */
  68#include <linux/init.h>		/* For __init/__exit/... */
  69#include <linux/fs.h>		/* For file operations */
  70#include <linux/isa.h>		/* For isa devices */
  71#include <linux/ioport.h>	/* For io-port access */
  72#include <linux/spinlock.h>	/* For spin_lock/spin_unlock/... */
  73#include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
  74#include <linux/io.h>		/* For inb/outb/... */
  75
  76/* Module and version information */
  77#define WATCHDOG_VERSION "1.20"
  78#define WATCHDOG_DATE "18 Feb 2007"
  79#define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  80#define WATCHDOG_NAME "pcwd"
  81#define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
  82
  83/*
  84 * It should be noted that PCWD_REVISION_B was removed because A and B
  85 * are essentially the same types of card, with the exception that B
  86 * has temperature reporting.  Since I didn't receive a Rev.B card,
  87 * the Rev.B card is not supported.  (It's a good thing too, as they
  88 * are no longer in production.)
  89 */
  90#define	PCWD_REVISION_A		1
  91#define	PCWD_REVISION_C		2
  92
  93/*
  94 * These are the auto-probe addresses available.
  95 *
  96 * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
  97 * Revision A has an address range of 2 addresses, while Revision C has 4.
  98 */
  99#define PCWD_ISA_NR_CARDS	3
 100static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 101
 102/*
 103 * These are the defines that describe the control status bits for the
 104 * PCI-PC Watchdog card.
 105*/
 106/* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
 107#define WD_WDRST		0x01	/* Previously reset state */
 108#define WD_T110			0x02	/* Temperature overheat sense */
 109#define WD_HRTBT		0x04	/* Heartbeat sense */
 110#define WD_RLY2			0x08	/* External relay triggered */
 111#define WD_SRLY2		0x80	/* Software external relay triggered */
 112/* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 113#define WD_REVC_WTRP		0x01	/* Watchdog Trip status */
 114#define WD_REVC_HRBT		0x02	/* Watchdog Heartbeat */
 115#define WD_REVC_TTRP		0x04	/* Temperature Trip status */
 116#define WD_REVC_RL2A		0x08	/* Relay 2 activated by
 117							on-board processor */
 118#define WD_REVC_RL1A		0x10	/* Relay 1 active */
 119#define WD_REVC_R2DS		0x40	/* Relay 2 disable */
 120#define WD_REVC_RLY2		0x80	/* Relay 2 activated? */
 121/* Port 2 : Control Status #2 */
 122#define WD_WDIS			0x10	/* Watchdog Disabled */
 123#define WD_ENTP			0x20	/* Watchdog Enable Temperature Trip */
 124#define WD_SSEL			0x40	/* Watchdog Switch Select
 125							(1:SW1 <-> 0:SW2) */
 126#define WD_WCMD			0x80	/* Watchdog Command Mode */
 127
 128/* max. time we give an ISA watchdog card to process a command */
 129/* 500ms for each 4 bit response (according to spec.) */
 130#define ISA_COMMAND_TIMEOUT     1000
 131
 132/* Watchdog's internal commands */
 133#define CMD_ISA_IDLE			0x00
 134#define CMD_ISA_VERSION_INTEGER		0x01
 135#define CMD_ISA_VERSION_TENTH		0x02
 136#define CMD_ISA_VERSION_HUNDRETH	0x03
 137#define CMD_ISA_VERSION_MINOR		0x04
 138#define CMD_ISA_SWITCH_SETTINGS		0x05
 139#define CMD_ISA_RESET_PC		0x06
 140#define CMD_ISA_ARM_0			0x07
 141#define CMD_ISA_ARM_30			0x08
 142#define CMD_ISA_ARM_60			0x09
 143#define CMD_ISA_DELAY_TIME_2SECS	0x0A
 144#define CMD_ISA_DELAY_TIME_4SECS	0x0B
 145#define CMD_ISA_DELAY_TIME_8SECS	0x0C
 146#define CMD_ISA_RESET_RELAYS		0x0D
 147
 148/* Watchdog's Dip Switch heartbeat values */
 149static const int heartbeat_tbl[] = {
 150	20,	/* OFF-OFF-OFF	= 20 Sec  */
 151	40,	/* OFF-OFF-ON	= 40 Sec  */
 152	60,	/* OFF-ON-OFF	=  1 Min  */
 153	300,	/* OFF-ON-ON	=  5 Min  */
 154	600,	/* ON-OFF-OFF	= 10 Min  */
 155	1800,	/* ON-OFF-ON	= 30 Min  */
 156	3600,	/* ON-ON-OFF	=  1 Hour */
 157	7200,	/* ON-ON-ON	=  2 hour */
 158};
 159
 160/*
 161 * We are using an kernel timer to do the pinging of the watchdog
 162 * every ~500ms. We try to set the internal heartbeat of the
 163 * watchdog to 2 ms.
 164 */
 165
 166#define WDT_INTERVAL (HZ/2+1)
 167
 168/* We can only use 1 card due to the /dev/watchdog restriction */
 169static int cards_found;
 170
 171/* internal variables */
 172static unsigned long open_allowed;
 173static char expect_close;
 174static int temp_panic;
 175
 176/* this is private data for each ISA-PC watchdog card */
 177static struct {
 178	char fw_ver_str[6];		/* The cards firmware version */
 179	int revision;			/* The card's revision */
 180	int supports_temp;		/* Whether or not the card has
 181						a temperature device */
 182	int command_mode;		/* Whether or not the card is in
 183						command mode */
 184	int boot_status;		/* The card's boot status */
 185	int io_addr;			/* The cards I/O address */
 186	spinlock_t io_lock;		/* the lock for io operations */
 187	struct timer_list timer;	/* The timer that pings the watchdog */
 188	unsigned long next_heartbeat;	/* the next_heartbeat for the timer */
 189} pcwd_private;
 190
 191/* module parameters */
 192#define QUIET	0	/* Default */
 193#define VERBOSE	1	/* Verbose */
 194#define DEBUG	2	/* print fancy stuff too */
 195static int debug = QUIET;
 196module_param(debug, int, 0);
 197MODULE_PARM_DESC(debug,
 198		"Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 199
 200/* default heartbeat = delay-time from dip-switches */
 201#define WATCHDOG_HEARTBEAT 0
 202static int heartbeat = WATCHDOG_HEARTBEAT;
 203module_param(heartbeat, int, 0);
 204MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
 205	"(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
 206				__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 207
 208static bool nowayout = WATCHDOG_NOWAYOUT;
 209module_param(nowayout, bool, 0);
 210MODULE_PARM_DESC(nowayout,
 211		"Watchdog cannot be stopped once started (default="
 212				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 213
 214/*
 215 *	Internal functions
 216 */
 217
 218static int send_isa_command(int cmd)
 219{
 220	int i;
 221	int control_status;
 222	int port0, last_port0;	/* Double read for stabilising */
 223
 224	if (debug >= DEBUG)
 225		pr_debug("sending following data cmd=0x%02x\n", cmd);
 226
 227	/* The WCMD bit must be 1 and the command is only 4 bits in size */
 228	control_status = (cmd & 0x0F) | WD_WCMD;
 229	outb_p(control_status, pcwd_private.io_addr + 2);
 230	udelay(ISA_COMMAND_TIMEOUT);
 231
 232	port0 = inb_p(pcwd_private.io_addr);
 233	for (i = 0; i < 25; ++i) {
 234		last_port0 = port0;
 235		port0 = inb_p(pcwd_private.io_addr);
 236
 237		if (port0 == last_port0)
 238			break;	/* Data is stable */
 239
 240		udelay(250);
 241	}
 242
 243	if (debug >= DEBUG)
 244		pr_debug("received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 245			 cmd, port0, last_port0);
 246
 247	return port0;
 248}
 249
 250static int set_command_mode(void)
 251{
 252	int i, found = 0, count = 0;
 253
 254	/* Set the card into command mode */
 255	spin_lock(&pcwd_private.io_lock);
 256	while ((!found) && (count < 3)) {
 257		i = send_isa_command(CMD_ISA_IDLE);
 258
 259		if (i == 0x00)
 260			found = 1;
 261		else if (i == 0xF3) {
 262			/* Card does not like what we've done to it */
 263			outb_p(0x00, pcwd_private.io_addr + 2);
 264			udelay(1200);	/* Spec says wait 1ms */
 265			outb_p(0x00, pcwd_private.io_addr + 2);
 266			udelay(ISA_COMMAND_TIMEOUT);
 267		}
 268		count++;
 269	}
 270	spin_unlock(&pcwd_private.io_lock);
 271	pcwd_private.command_mode = found;
 272
 273	if (debug >= DEBUG)
 274		pr_debug("command_mode=%d\n", pcwd_private.command_mode);
 275
 276	return found;
 277}
 278
 279static void unset_command_mode(void)
 280{
 281	/* Set the card into normal mode */
 282	spin_lock(&pcwd_private.io_lock);
 283	outb_p(0x00, pcwd_private.io_addr + 2);
 284	udelay(ISA_COMMAND_TIMEOUT);
 285	spin_unlock(&pcwd_private.io_lock);
 286
 287	pcwd_private.command_mode = 0;
 288
 289	if (debug >= DEBUG)
 290		pr_debug("command_mode=%d\n", pcwd_private.command_mode);
 291}
 292
 293static inline void pcwd_check_temperature_support(void)
 294{
 295	if (inb(pcwd_private.io_addr) != 0xF0)
 296		pcwd_private.supports_temp = 1;
 297}
 298
 299static inline void pcwd_get_firmware(void)
 300{
 301	int one, ten, hund, minor;
 302
 303	strcpy(pcwd_private.fw_ver_str, "ERROR");
 304
 305	if (set_command_mode()) {
 306		one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 307		ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 308		hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 309		minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 310		sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
 311					one, ten, hund, minor);
 312	}
 313	unset_command_mode();
 314
 315	return;
 316}
 317
 318static inline int pcwd_get_option_switches(void)
 319{
 320	int option_switches = 0;
 321
 322	if (set_command_mode()) {
 323		/* Get switch settings */
 324		option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 325	}
 326
 327	unset_command_mode();
 328	return option_switches;
 329}
 330
 331static void pcwd_show_card_info(void)
 332{
 333	int option_switches;
 334
 335	/* Get some extra info from the hardware (in command/debug/diag mode) */
 336	if (pcwd_private.revision == PCWD_REVISION_A)
 337		pr_info("ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
 338			pcwd_private.io_addr);
 339	else if (pcwd_private.revision == PCWD_REVISION_C) {
 340		pcwd_get_firmware();
 341		pr_info("ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 342			pcwd_private.io_addr, pcwd_private.fw_ver_str);
 343		option_switches = pcwd_get_option_switches();
 344		pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 345			option_switches,
 346			((option_switches & 0x10) ? "ON" : "OFF"),
 347			((option_switches & 0x08) ? "ON" : "OFF"));
 348
 349		/* Reprogram internal heartbeat to 2 seconds */
 350		if (set_command_mode()) {
 351			send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 352			unset_command_mode();
 353		}
 354	}
 355
 356	if (pcwd_private.supports_temp)
 357		pr_info("Temperature Option Detected\n");
 358
 359	if (pcwd_private.boot_status & WDIOF_CARDRESET)
 360		pr_info("Previous reboot was caused by the card\n");
 361
 362	if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 363		pr_emerg("Card senses a CPU Overheat. Panicking!\n");
 364		pr_emerg("CPU Overheat\n");
 365	}
 366
 367	if (pcwd_private.boot_status == 0)
 368		pr_info("No previous trip detected - Cold boot or reset\n");
 369}
 370
 371static void pcwd_timer_ping(struct timer_list *unused)
 372{
 373	int wdrst_stat;
 374
 375	/* If we got a heartbeat pulse within the WDT_INTERVAL
 376	 * we agree to ping the WDT */
 377	if (time_before(jiffies, pcwd_private.next_heartbeat)) {
 378		/* Ping the watchdog */
 379		spin_lock(&pcwd_private.io_lock);
 380		if (pcwd_private.revision == PCWD_REVISION_A) {
 381			/*  Rev A cards are reset by setting the
 382			    WD_WDRST bit in register 1 */
 383			wdrst_stat = inb_p(pcwd_private.io_addr);
 384			wdrst_stat &= 0x0F;
 385			wdrst_stat |= WD_WDRST;
 386
 387			outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 388		} else {
 389			/* Re-trigger watchdog by writing to port 0 */
 390			outb_p(0x00, pcwd_private.io_addr);
 391		}
 392
 393		/* Re-set the timer interval */
 394		mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 395
 396		spin_unlock(&pcwd_private.io_lock);
 397	} else {
 398		pr_warn("Heartbeat lost! Will not ping the watchdog\n");
 399	}
 400}
 401
 402static int pcwd_start(void)
 403{
 404	int stat_reg;
 405
 406	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 407
 408	/* Start the timer */
 409	mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 410
 411	/* Enable the port */
 412	if (pcwd_private.revision == PCWD_REVISION_C) {
 413		spin_lock(&pcwd_private.io_lock);
 414		outb_p(0x00, pcwd_private.io_addr + 3);
 415		udelay(ISA_COMMAND_TIMEOUT);
 416		stat_reg = inb_p(pcwd_private.io_addr + 2);
 417		spin_unlock(&pcwd_private.io_lock);
 418		if (stat_reg & WD_WDIS) {
 419			pr_info("Could not start watchdog\n");
 420			return -EIO;
 421		}
 422	}
 423
 424	if (debug >= VERBOSE)
 425		pr_debug("Watchdog started\n");
 426
 427	return 0;
 428}
 429
 430static int pcwd_stop(void)
 431{
 432	int stat_reg;
 433
 434	/* Stop the timer */
 435	del_timer(&pcwd_private.timer);
 436
 437	/*  Disable the board  */
 438	if (pcwd_private.revision == PCWD_REVISION_C) {
 439		spin_lock(&pcwd_private.io_lock);
 440		outb_p(0xA5, pcwd_private.io_addr + 3);
 441		udelay(ISA_COMMAND_TIMEOUT);
 442		outb_p(0xA5, pcwd_private.io_addr + 3);
 443		udelay(ISA_COMMAND_TIMEOUT);
 444		stat_reg = inb_p(pcwd_private.io_addr + 2);
 445		spin_unlock(&pcwd_private.io_lock);
 446		if ((stat_reg & WD_WDIS) == 0) {
 447			pr_info("Could not stop watchdog\n");
 448			return -EIO;
 449		}
 450	}
 451
 452	if (debug >= VERBOSE)
 453		pr_debug("Watchdog stopped\n");
 454
 455	return 0;
 456}
 457
 458static int pcwd_keepalive(void)
 459{
 460	/* user land ping */
 461	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 462
 463	if (debug >= DEBUG)
 464		pr_debug("Watchdog keepalive signal send\n");
 465
 466	return 0;
 467}
 468
 469static int pcwd_set_heartbeat(int t)
 470{
 471	if (t < 2 || t > 7200) /* arbitrary upper limit */
 472		return -EINVAL;
 473
 474	heartbeat = t;
 475
 476	if (debug >= VERBOSE)
 477		pr_debug("New heartbeat: %d\n", heartbeat);
 478
 479	return 0;
 480}
 481
 482static int pcwd_get_status(int *status)
 483{
 484	int control_status;
 485
 486	*status = 0;
 487	spin_lock(&pcwd_private.io_lock);
 488	if (pcwd_private.revision == PCWD_REVISION_A)
 489		/* Rev A cards return status information from
 490		 * the base register, which is used for the
 491		 * temperature in other cards. */
 492		control_status = inb(pcwd_private.io_addr);
 493	else {
 494		/* Rev C cards return card status in the base
 495		 * address + 1 register. And use different bits
 496		 * to indicate a card initiated reset, and an
 497		 * over-temperature condition. And the reboot
 498		 * status can be reset. */
 499		control_status = inb(pcwd_private.io_addr + 1);
 500	}
 501	spin_unlock(&pcwd_private.io_lock);
 502
 503	if (pcwd_private.revision == PCWD_REVISION_A) {
 504		if (control_status & WD_WDRST)
 505			*status |= WDIOF_CARDRESET;
 506
 507		if (control_status & WD_T110) {
 508			*status |= WDIOF_OVERHEAT;
 509			if (temp_panic) {
 510				pr_info("Temperature overheat trip!\n");
 511				kernel_power_off();
 512			}
 513		}
 514	} else {
 515		if (control_status & WD_REVC_WTRP)
 516			*status |= WDIOF_CARDRESET;
 517
 518		if (control_status & WD_REVC_TTRP) {
 519			*status |= WDIOF_OVERHEAT;
 520			if (temp_panic) {
 521				pr_info("Temperature overheat trip!\n");
 522				kernel_power_off();
 523			}
 524		}
 525	}
 526
 527	return 0;
 528}
 529
 530static int pcwd_clear_status(void)
 531{
 532	int control_status;
 533
 534	if (pcwd_private.revision == PCWD_REVISION_C) {
 535		spin_lock(&pcwd_private.io_lock);
 536
 537		if (debug >= VERBOSE)
 538			pr_info("clearing watchdog trip status\n");
 539
 540		control_status = inb_p(pcwd_private.io_addr + 1);
 541
 542		if (debug >= DEBUG) {
 543			pr_debug("status was: 0x%02x\n", control_status);
 544			pr_debug("sending: 0x%02x\n",
 545				 (control_status & WD_REVC_R2DS));
 546		}
 547
 548		/* clear reset status & Keep Relay 2 disable state as it is */
 549		outb_p((control_status & WD_REVC_R2DS),
 550						pcwd_private.io_addr + 1);
 551
 552		spin_unlock(&pcwd_private.io_lock);
 553	}
 554	return 0;
 555}
 556
 557static int pcwd_get_temperature(int *temperature)
 558{
 559	/* check that port 0 gives temperature info and no command results */
 560	if (pcwd_private.command_mode)
 561		return -1;
 562
 563	*temperature = 0;
 564	if (!pcwd_private.supports_temp)
 565		return -ENODEV;
 566
 567	/*
 568	 * Convert celsius to fahrenheit, since this was
 569	 * the decided 'standard' for this return value.
 570	 */
 571	spin_lock(&pcwd_private.io_lock);
 572	*temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 573	spin_unlock(&pcwd_private.io_lock);
 574
 575	if (debug >= DEBUG) {
 576		pr_debug("temperature is: %d F\n", *temperature);
 577	}
 578
 579	return 0;
 580}
 581
 582/*
 583 *	/dev/watchdog handling
 584 */
 585
 586static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 587{
 588	int rv;
 589	int status;
 590	int temperature;
 591	int new_heartbeat;
 592	int __user *argp = (int __user *)arg;
 593	static const struct watchdog_info ident = {
 594		.options =		WDIOF_OVERHEAT |
 595					WDIOF_CARDRESET |
 596					WDIOF_KEEPALIVEPING |
 597					WDIOF_SETTIMEOUT |
 598					WDIOF_MAGICCLOSE,
 599		.firmware_version =	1,
 600		.identity =		"PCWD",
 601	};
 602
 603	switch (cmd) {
 604	case WDIOC_GETSUPPORT:
 605		if (copy_to_user(argp, &ident, sizeof(ident)))
 606			return -EFAULT;
 607		return 0;
 608
 609	case WDIOC_GETSTATUS:
 610		pcwd_get_status(&status);
 611		return put_user(status, argp);
 612
 613	case WDIOC_GETBOOTSTATUS:
 614		return put_user(pcwd_private.boot_status, argp);
 615
 616	case WDIOC_GETTEMP:
 617		if (pcwd_get_temperature(&temperature))
 618			return -EFAULT;
 619
 620		return put_user(temperature, argp);
 621
 622	case WDIOC_SETOPTIONS:
 623		if (pcwd_private.revision == PCWD_REVISION_C) {
 624			if (get_user(rv, argp))
 625				return -EFAULT;
 626
 627			if (rv & WDIOS_DISABLECARD) {
 628				status = pcwd_stop();
 629				if (status < 0)
 630					return status;
 631			}
 632			if (rv & WDIOS_ENABLECARD) {
 633				status = pcwd_start();
 634				if (status < 0)
 635					return status;
 636			}
 637			if (rv & WDIOS_TEMPPANIC)
 638				temp_panic = 1;
 639		}
 640		return -EINVAL;
 641
 642	case WDIOC_KEEPALIVE:
 643		pcwd_keepalive();
 644		return 0;
 645
 646	case WDIOC_SETTIMEOUT:
 647		if (get_user(new_heartbeat, argp))
 648			return -EFAULT;
 649
 650		if (pcwd_set_heartbeat(new_heartbeat))
 651			return -EINVAL;
 652
 653		pcwd_keepalive();
 654		fallthrough;
 655
 656	case WDIOC_GETTIMEOUT:
 657		return put_user(heartbeat, argp);
 658
 659	default:
 660		return -ENOTTY;
 661	}
 662
 663	return 0;
 664}
 665
 666static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 667			  loff_t *ppos)
 668{
 669	if (len) {
 670		if (!nowayout) {
 671			size_t i;
 672
 673			/* In case it was set long ago */
 674			expect_close = 0;
 675
 676			for (i = 0; i != len; i++) {
 677				char c;
 678
 679				if (get_user(c, buf + i))
 680					return -EFAULT;
 681				if (c == 'V')
 682					expect_close = 42;
 683			}
 684		}
 685		pcwd_keepalive();
 686	}
 687	return len;
 688}
 689
 690static int pcwd_open(struct inode *inode, struct file *file)
 691{
 692	if (test_and_set_bit(0, &open_allowed))
 693		return -EBUSY;
 694	if (nowayout)
 695		__module_get(THIS_MODULE);
 696	/* Activate */
 697	pcwd_start();
 698	pcwd_keepalive();
 699	return stream_open(inode, file);
 700}
 701
 702static int pcwd_close(struct inode *inode, struct file *file)
 703{
 704	if (expect_close == 42)
 705		pcwd_stop();
 706	else {
 707		pr_crit("Unexpected close, not stopping watchdog!\n");
 708		pcwd_keepalive();
 709	}
 710	expect_close = 0;
 711	clear_bit(0, &open_allowed);
 712	return 0;
 713}
 714
 715/*
 716 *	/dev/temperature handling
 717 */
 718
 719static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 720			 loff_t *ppos)
 721{
 722	int temperature;
 723
 724	if (pcwd_get_temperature(&temperature))
 725		return -EFAULT;
 726
 727	if (copy_to_user(buf, &temperature, 1))
 728		return -EFAULT;
 729
 730	return 1;
 731}
 732
 733static int pcwd_temp_open(struct inode *inode, struct file *file)
 734{
 735	if (!pcwd_private.supports_temp)
 736		return -ENODEV;
 737
 738	return stream_open(inode, file);
 739}
 740
 741static int pcwd_temp_close(struct inode *inode, struct file *file)
 742{
 743	return 0;
 744}
 745
 746/*
 747 *	Kernel Interfaces
 748 */
 749
 750static const struct file_operations pcwd_fops = {
 751	.owner		= THIS_MODULE,
 752	.llseek		= no_llseek,
 753	.write		= pcwd_write,
 754	.unlocked_ioctl	= pcwd_ioctl,
 755	.compat_ioctl	= compat_ptr_ioctl,
 756	.open		= pcwd_open,
 757	.release	= pcwd_close,
 758};
 759
 760static struct miscdevice pcwd_miscdev = {
 761	.minor =	WATCHDOG_MINOR,
 762	.name =		"watchdog",
 763	.fops =		&pcwd_fops,
 764};
 765
 766static const struct file_operations pcwd_temp_fops = {
 767	.owner		= THIS_MODULE,
 768	.llseek		= no_llseek,
 769	.read		= pcwd_temp_read,
 770	.open		= pcwd_temp_open,
 771	.release	= pcwd_temp_close,
 772};
 773
 774static struct miscdevice temp_miscdev = {
 775	.minor =	TEMP_MINOR,
 776	.name =		"temperature",
 777	.fops =		&pcwd_temp_fops,
 778};
 779
 780/*
 781 *	Init & exit routines
 782 */
 783
 784static inline int get_revision(void)
 785{
 786	int r = PCWD_REVISION_C;
 787
 788	spin_lock(&pcwd_private.io_lock);
 789	/* REV A cards use only 2 io ports; test
 790	 * presumes a floating bus reads as 0xff. */
 791	if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 792	    (inb(pcwd_private.io_addr + 3) == 0xFF))
 793		r = PCWD_REVISION_A;
 794	spin_unlock(&pcwd_private.io_lock);
 795
 796	return r;
 797}
 798
 799/*
 800 *  The ISA cards have a heartbeat bit in one of the registers, which
 801 *  register is card dependent.  The heartbeat bit is monitored, and if
 802 *  found, is considered proof that a Berkshire card has been found.
 803 *  The initial rate is once per second at board start up, then twice
 804 *  per second for normal operation.
 805 */
 806static int pcwd_isa_match(struct device *dev, unsigned int id)
 807{
 808	int base_addr = pcwd_ioports[id];
 809	int port0, last_port0;	/* Reg 0, in case it's REV A */
 810	int port1, last_port1;	/* Register 1 for REV C cards */
 811	int i;
 812	int retval;
 813
 814	if (debug >= DEBUG)
 815		pr_debug("pcwd_isa_match id=%d\n", id);
 816
 817	if (!request_region(base_addr, 4, "PCWD")) {
 818		pr_info("Port 0x%04x unavailable\n", base_addr);
 819		return 0;
 820	}
 821
 822	retval = 0;
 823
 824	port0 = inb_p(base_addr);	/* For REV A boards */
 825	port1 = inb_p(base_addr + 1);	/* For REV C boards */
 826	if (port0 != 0xff || port1 != 0xff) {
 827		/* Not an 'ff' from a floating bus, so must be a card! */
 828		for (i = 0; i < 4; ++i) {
 829
 830			msleep(500);
 831
 832			last_port0 = port0;
 833			last_port1 = port1;
 834
 835			port0 = inb_p(base_addr);
 836			port1 = inb_p(base_addr + 1);
 837
 838			/* Has either hearbeat bit changed?  */
 839			if ((port0 ^ last_port0) & WD_HRTBT ||
 840			    (port1 ^ last_port1) & WD_REVC_HRBT) {
 841				retval = 1;
 842				break;
 843			}
 844		}
 845	}
 846	release_region(base_addr, 4);
 847
 848	return retval;
 849}
 850
 851static int pcwd_isa_probe(struct device *dev, unsigned int id)
 852{
 853	int ret;
 854
 855	if (debug >= DEBUG)
 856		pr_debug("pcwd_isa_probe id=%d\n", id);
 857
 858	cards_found++;
 859	if (cards_found == 1)
 860		pr_info("v%s Ken Hollis (kenji@bitgate.com)\n",
 861							WATCHDOG_VERSION);
 862
 863	if (cards_found > 1) {
 864		pr_err("This driver only supports 1 device\n");
 865		return -ENODEV;
 866	}
 867
 868	if (pcwd_ioports[id] == 0x0000) {
 869		pr_err("No I/O-Address for card detected\n");
 870		return -ENODEV;
 871	}
 872	pcwd_private.io_addr = pcwd_ioports[id];
 873
 874	spin_lock_init(&pcwd_private.io_lock);
 875
 876	/* Check card's revision */
 877	pcwd_private.revision = get_revision();
 878
 879	if (!request_region(pcwd_private.io_addr,
 880		(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 881		pr_err("I/O address 0x%04x already in use\n",
 882		       pcwd_private.io_addr);
 883		ret = -EIO;
 884		goto error_request_region;
 885	}
 886
 887	/* Initial variables */
 888	pcwd_private.supports_temp = 0;
 889	temp_panic = 0;
 890	pcwd_private.boot_status = 0x0000;
 891
 892	/* get the boot_status */
 893	pcwd_get_status(&pcwd_private.boot_status);
 894
 895	/* clear the "card caused reboot" flag */
 896	pcwd_clear_status();
 897
 898	timer_setup(&pcwd_private.timer, pcwd_timer_ping, 0);
 899
 900	/*  Disable the board  */
 901	pcwd_stop();
 902
 903	/*  Check whether or not the card supports the temperature device */
 904	pcwd_check_temperature_support();
 905
 906	/* Show info about the card itself */
 907	pcwd_show_card_info();
 908
 909	/* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 910	if (heartbeat == 0)
 911		heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 912
 913	/* Check that the heartbeat value is within it's range;
 914	   if not reset to the default */
 915	if (pcwd_set_heartbeat(heartbeat)) {
 916		pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 917		pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
 918			WATCHDOG_HEARTBEAT);
 919	}
 920
 921	if (pcwd_private.supports_temp) {
 922		ret = misc_register(&temp_miscdev);
 923		if (ret) {
 924			pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 925			       TEMP_MINOR, ret);
 926			goto error_misc_register_temp;
 927		}
 928	}
 929
 930	ret = misc_register(&pcwd_miscdev);
 931	if (ret) {
 932		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 933		       WATCHDOG_MINOR, ret);
 934		goto error_misc_register_watchdog;
 935	}
 936
 937	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 938		heartbeat, nowayout);
 939
 940	return 0;
 941
 942error_misc_register_watchdog:
 943	if (pcwd_private.supports_temp)
 944		misc_deregister(&temp_miscdev);
 945error_misc_register_temp:
 946	release_region(pcwd_private.io_addr,
 947			(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 948error_request_region:
 949	pcwd_private.io_addr = 0x0000;
 950	cards_found--;
 951	return ret;
 952}
 953
 954static int pcwd_isa_remove(struct device *dev, unsigned int id)
 955{
 956	if (debug >= DEBUG)
 957		pr_debug("pcwd_isa_remove id=%d\n", id);
 958
 959	if (!pcwd_private.io_addr)
 960		return 1;
 961
 962	/*  Disable the board  */
 963	if (!nowayout)
 964		pcwd_stop();
 965
 966	/* Deregister */
 967	misc_deregister(&pcwd_miscdev);
 968	if (pcwd_private.supports_temp)
 969		misc_deregister(&temp_miscdev);
 970	release_region(pcwd_private.io_addr,
 971			(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 972	pcwd_private.io_addr = 0x0000;
 973	cards_found--;
 974
 975	return 0;
 976}
 977
 978static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
 979{
 980	if (debug >= DEBUG)
 981		pr_debug("pcwd_isa_shutdown id=%d\n", id);
 982
 983	pcwd_stop();
 984}
 985
 986static struct isa_driver pcwd_isa_driver = {
 987	.match		= pcwd_isa_match,
 988	.probe		= pcwd_isa_probe,
 989	.remove		= pcwd_isa_remove,
 990	.shutdown	= pcwd_isa_shutdown,
 991	.driver		= {
 992		.owner	= THIS_MODULE,
 993		.name	= WATCHDOG_NAME,
 994	},
 995};
 996
 997module_isa_driver(pcwd_isa_driver, PCWD_ISA_NR_CARDS);
 998
 999MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
1000		"Wim Van Sebroeck <wim@iguana.be>");
1001MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1002MODULE_VERSION(WATCHDOG_VERSION);
1003MODULE_LICENSE("GPL");